1///////////////////////////////////////////////////////////////////////////////
2/// \file is_noncopyable.hpp
3/// Utility for detecting when types are non-copyable
4//
5// Copyright 2008 Eric Niebler. Distributed under the Boost
6// Software License, Version 1.0. (See accompanying file
7// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
8
9#ifndef BOOST_PROTO_DETAIL_IS_NONCOPYABLE_HPP_EAN_19_07_2012
10#define BOOST_PROTO_DETAIL_IS_NONCOPYABLE_HPP_EAN_19_07_2012
11
12#include <boost/noncopyable.hpp>
13#include <boost/mpl/or.hpp>
14#include <boost/mpl/bool.hpp>
15#include <boost/type_traits/is_base_of.hpp>
16#include <boost/type_traits/is_abstract.hpp>
17#include <boost/type_traits/is_function.hpp>
18#include <boost/proto/proto_fwd.hpp>
19
20namespace boost { namespace proto { namespace detail
21{
22 // All classes derived from std::ios_base have these public nested types,
23 // and are non-copyable. This is an imperfect test, but it's the best we
24 // we can do.
25 template<typename T>
26 yes_type check_is_iostream(
27 typename T::failure *
28 , typename T::Init *
29 , typename T::fmtflags *
30 , typename T::iostate *
31 , typename T::openmode *
32 , typename T::seekdir *
33 );
34
35 template<typename T>
36 no_type check_is_iostream(...);
37
38 template<typename T>
39 struct is_iostream
40 {
41 static bool const value = sizeof(yes_type) == sizeof(check_is_iostream<T>(0,0,0,0,0,0));
42 typedef mpl::bool_<value> type;
43 };
44
45 /// INTERNAL ONLY
46 // This should be a customization point. And it serves the same purpose
47 // as the is_noncopyable trait in Boost.Foreach.
48 template<typename T>
49 struct is_noncopyable
50 : mpl::or_<
51 is_function<T>
52 , is_abstract<T>
53 , is_iostream<T>
54 , is_base_of<noncopyable, T>
55 >
56 {};
57
58 template<typename T, std::size_t N>
59 struct is_noncopyable<T[N]>
60 : mpl::true_
61 {};
62
63}}}
64
65#endif
66